Display device with a plurality of 180u deg. windings angularly displaced from one another around an annular core



Dec. 6, 1966 E. KNOTOWICZ 3,290,632

A. DISPLAY DEVICE WITH A PLURALITY OF 180 WINDINGS ANGULARLY DISPLACED FROM ONE ANOTHER AROUND AN ANNULAR CORE Filed Oct. 21, 1964 2 Sheets-Sheet 1 FIG?) I N VENTOR.

ALOYSIUS E, KNOTOWICZ ATTORNEYS Dec. 6, 6 A E. KNOTOWICZ 3,290,632

DISPLAY DEVICE WITH A PLURALI'I'Y OF 180 WINDINGS ANGULARLY DISPLACED FROM ONE ANOTHER AROUND AN ANNULAR CORE 2 Sheets-Sheet 2 Filed Oct. 21, 1964 INVENTOR. ALOYEIUS E. KNOTOWICZ ATTORNEYS United States Patent 3,290,632 DISPLAY DEVICE WITH A PLURALITY OF 180 WINDINGS ANGULARLY DISPLACED FROM ONE ANOTHER AROUND AN ANNULAR CORE Aloysius Edward Knotowicz, Torrington, Conn., assignor to The Patent Button Company, Waterbury, Conu., a

corporation of Connecticut Filed Oct. 21, 1964, Ser. No. 405,491 2 Claims. (Cl. 335-272) This invention relates in general to data display devices and more particularly pertains to an electromagnetically actuated indicator for displaying symbols selected in response to electric signals.

In the conventional electromagnetically actuated indicator, a stationary electromagnetic structure, termed a stator, is employed that is able, in response to an appropriate electrical input, to produce any one of a plurality of discretely oriented magnetic fields. The stator of the conventional indicator utilizes a plurality of electromagnets symmetrically arranged around a circular core, the circular configuration of electromagnets permitting the establishment of a number of discretely oriented magnetic fields in response to the application of current to the windings of the electromagnets. A rotor having a character bearing drum attached to it, rotates to a position determined by the magnetic field orientation so that one of the characters on the wheel is presented in a window of the indicators housing. The rotor employs a permanent magnet which is caused to rotate into alignment with the magnetic field esablished by the stator. The conventional electromagnetic indicator requires a plurality of electrical connections to the windings of the stator and requires a somewhat complex switching arrangement in order to activate selected coils. Y

The present invention resides in a simplified stator having an annular core upon which is mounted a plurality of separatelyenergizable windings. The windings overlap and each winding covers an arc of about 180 so that when any coil is energized, it establishes a magnetic field oriented differently from the magnetic field that can be established by any of the other windings on the core. By reversing the current flow in a winding, the direction of the stators magnetic field is reversed. Each winding, therefore, permits the establishment of either of two dis cretely oriented magnetic fields, depending upon the polarity of the voltage applied to the winding.

By arranging the windings in overlapping relation upon the stators core, a simple, efiicient structure is produced which can be manufactured at low cost. The invention, both as to its construction and its mode of operation, can be better understood from the following exposition which is intended to be read in connection with the accompanying drawings in which:

FIG. 1 depicts, in perspective, an indicator of the type utilizing the invention;

FIG. 2 is an exploded view of an embodiment of the invention;

FIG. 3 illustrates a cross-sectional view of the inventions embodiment;

FIG. 4 depicts the arrangement of windings of the stator;

FIG. 5 shows a preferred arrangement for energizing the windings; and

FIG. 6 is a view that has been partly broken away to show an alternative arrangement of stator windings.

Referring now to FIGS. 1, 2 and 3 of the drawings, there is shown a thin hol-low cylindrical housing 1 having a rectangular window 2 through which symbols carried by a rotor may be viewed. Housing 1 is a narrow hollow cylinder that is closed at one end by an integral end wall 4 and at its other end is covered by a plate 5 hav- -a toroidal core 20.

ing a central circular aperture. An axle 6 is secured at the center of circular end wall 4 and upon the axle is mounted the rotor 7 of the indicator. The rotor is an assemblage having a salient pole magnet 8 secured to a hub 9, the hub having a central bore for receiving the axle 6 and permitting the rotor to turn freely about the axle. Secured to the hub is a drum 10 whose periphery is marked with characters, such as numerals, which are to be displayed in the window of the housing. Usually, the characters are of such size as to permit only one of them to be fully presented in the window, as indicated in FIG. 1.

Secured within the housing is a stator 11 having electrical leads 12 that are brought out of the housing through an insulating panel 13 in end wall 4. The stator, depicted in FIG. 4 without its plastic em bedment, employs a number of windings 14, 15, 16, 17 and 18 mounted upon If desired, the windings may be embedded in a plastic material, as shown, to prevent the windings from shifting and to aid in heat transfer. Each winding covers an arc of about and the windings are arranged on the core in overlapping relation. Each winding, when energized by a flow of electrical current, causes a magnetic field to be established having a discrete orientation. For example, where winding 18 is energized, a magnetic field, represented by the stippling in FIG. 4, is established between the ends of the winding. The salient pole magnet, shown in phantom in FIG. 4, is located within the space encircled by the core and is constrained to rotate into alignment with the magnetic field. By reversing the direction of current flow in the winding, the magnetic field direction is reversed. The salient pole magnet, therefore, can assume one of two possible aligned positions when the winding is energized, depending upon the direction of current flow in the winding. The number of aligned positions of the rotors magnet that is required by the indicator is usually determined by the number of characters that are to be displayed. For example, where ten different numerals are to be displayed, five windings would be provided on the core. The five windings are preferably arranged on the core as indicated in FIG. 4 so that the windings determine ten positions for the rotor that are evenly spaced around a circle. The ten evenly spaced positions are obtained by displacing each semicircular Winding by 36 relative to the immediately subjacent winding. In FIG. 4, for example, winding 15 is displaced 36 relative to subjacent winding 14, winding 16 is displaced 36 relative to subjacent winding 15, and so on. To obtain ten positions with five windings, the connections to the windings must be arranged so that the energizing potential applied to each winding can be reversed in polarity. For this purpose, the switching arrangement of FIG. 5 is convenient as it permits all the windings to have a common grounded terminal. The switch employed in that arrangement has two rotatable arms 21 and 22 which are interconnected to turn together. Switch arm 22 rides upon an arcuate conductive track 23 whenever switch arm 21 is positioned upon contacts 1 through 5. Whenever switch arm 21 is positioned upon the other contacts, 6 through 0, switch arm 22 rides upon arcuate conductive track 24. Sources of electrical potential, here represented by batteries 25 and 26 are connected to the arcuate tracks so that the potential of one track is positive relative to ground and the potential of the other track is negative relative to ground. Therefore, when arm 21 is at stations 1 through 5, the current flow in the windings is opposite to the current flow in the windings when arm 21 is at stations 6 through 0.

When it is desired to operate a ten position indicator Without having to provide for polarity reversals in the potential applied to the windings, the stator of the indicator is provided with 10 windings overlapping in the manner shown in FIG. 5 and each winding is displaced 36 relative to the immediately subjacent winding. Each winding may then have one of its terminals connected in com mon and the other terminal may be connected to one station of a ten station switch.

The core 20 of the-stator, FIG. 4, is preferably of a non-magnetic material so as not to present a bypassing path or short circuit for the magnetic flux of the energized winding. Where it is desired to conserve power, the stator shown in FIG. 6 may be substituted. In the FIG. 6 stator, the core 30 is constructed of a material, such as soft iron, that is highly permeable to magnetic flux. Five coils 31, 32, 33, 34, 35 are disposed upon the core, each coil covering the full (360) extent of the core. The innermost coil 31 is wrapped upon toroidal core 30 and the coil has two taps, 30A and 30B, spaced apart by 180", which are brought out to permit the coil to be electrically energized. Coil 32 is wrapped over coil 31 and has two taps, 32A and 32B, displaced by 36 from corresponding taps on the subjacent coil. Similarly, coil 33 is superposed on coil 32, coil 34 is wound over coil 33, and coil 35 is wrapped over coil 34. Each of the coils 33, 34 and 35, have two taps, designated by suffixes A and B, that are displaced by 36 from corresponding taps on the coil immediately below. Each coil, in effect, consists of two 180 windings arranged so that both windings are simultaneously energized. When energized, the two windings set up opposingly directed flux lines in the core. That is, the magnetic lines of flux set up in the core by one of the windings are opposite in direction (viz. clockwise or counterclockwise) to the magnetic lines of flux set up in the core by the other winding.

It is evident that the number of windings employed in the stator is dependent upon the number of symbols to be displayed by the indicator. Further, it is evident that the positions of the rotor established by the stators magnetic fields need not be evenly spaced about a circle nor need those positions he symmetrical about the circle. Such changes, and others, are apparent to those skilled in the art and do not depart from the essential nature of the invention. It is intended, therefore, that the invention not be confined to the precise embodiment depicted in the drawings but rather that the inventions scope be limited by the appended claims.

' What is claimed is:

1. In an electromagnetic indicator of the type utilizing (l) a stator having windings mounted upon an annular core, the stator establishing any one of a plurality of discretely oriented magnetic fields upon the electrical energization of a selected one of the windings,

and

(2) a rotor having a salient pole magnet mounted to pivot within the annular core whereby the magnet rotates into alignment with the magnetic field established by the stator,

the improvement wherein (a) each winding of the stator extends over an 180 arc of the core that is angularly displaced relative to the 180 arc occupied by any of the other windings, and I (b) the windings are in overlapping relationship whereby each winding establishes a magnetic field Whose orientation is different from the orientation of the magnetic fields established by the other windings.

2. In an electromagnetic indicator of the type utilizing (l) a stator having windings mounted upon an annular core, the stator establishing any one of a plurality of discretely oriented magnetic fields upon electrical energization of a selected one of the windings, and

(2) arotor having a salient pole magnet mounted to pivot within the space encircled by the annular core whereby the magnet rotates into alignment with the stators magnetic field,

the improvement in which (a) each winding of the stator extends over an 180 arc of the core, and

(b) each winding, excepting the innermost one, surrounds a portion of the subjacent winding so that the 180 are over which the superposed winding extends is angularly displaced relative to the 180 arc of the subjacent winding whereby each winding establishes a magnetic field whose orientation is different from the orientation of the magnetic fields established by the other windings.

40 No references cited.

BERNARD A. GILHEANY, Primary Examiner.

H. LEWITTER, Assistant Examiner. 

1. IN AN ELECTROMAGNETIC INDICATOR OF THE TYPE UTILIZING (1) A STATOR HAVING WINDINGS MOUNTED UPON AN ANNULAR CORE, THE STATOR ESTABLISHING ANY ONE OF A PLURALITY OF DISCRETELY ORIENTED MAGNETIC FIELD UPON THE ELECTRICAL ENERGIZATION OF A SELECTED ONE OF THE WINDINGS, AND (2) A ROTOR HAVING A SALIENT POLE MAGNET MOUNTED TO PIVOT WITHIN THE ANNULAR CORE WHEREBY THE MAGNET ROTATES INTO ALIGNMENT WITH THE MAGNETIC FIELD ESTABLISHED BY THE STATOR, THE IMPROVEMENT WHEREIN (A) EACH WINDING OF THE STATOR EXTENDS OVER AN 180* ARC OF THE CORE THAT IS ANGULARLY DISPLACED RELATIVE TO THE 180* ARC OCCUPIED BY ANY OF THE OTHER WINDINGS, AND (B) THE WINDINGS ARE IN OVERLAPPING RELATIONSHIP WHEREBY EACH WINDING ESTABLISHES A MAGNETIC FIELD WHOSE ORIENTATION IS DIFFERENT FROM THE ORIENTATION OF THE MAGNETIC FIELDS ESTABLISHED BY THE OTHER WINDINGS. 